More than 1.5m children under five die each year because they lack access to safe water and proper sanitation, says the United Nations children's agency.
In a report, Unicef says that despite some successes, a billion people worldwide do not have access to safe drinking water from protected sources.
More than 1.2 billion people have gained access to safe water since 1990.
But sub-Saharan Africa remains a major area of concern, especially countries affected by conflict.
A Unicef deputy-director, Vanessa Tobin, gave the example of Niger, where only 13% of the population has access to toilets of an acceptable standard, or better.
She said it "certainly is a contributing factor in the cholera outbreaks" in Niger.Full story
BBC 28 Sep 2006.